GEC Z8526
Lantern acquired in September 2006.
Thanks to Steve Rowe for letting me have this lantern. Originally fitted in Topsham Road, Exeter, the lantern is believed to have been fitted with a 250 Watt SON lamp for its entire life although the actual design dates from mercury days. It was removed when the lighting was being upgraded - Philips Iridiums with dimmable electronic gear were the chosen replacement lanterns. This GEC 'Turtle' was popular in its day; however, it did not make much of an impression on the Derbyshire street lighting scene due to the Atlas/Thorn Alpha 3 being a preferred main road lantern (an exception was the Babington Lane area, although these had been replaced with Z9554Ms by 1984). Examples did exist in Chesterfield Town Centre, however.
The design of the lantern looks to have been inspired by Atlas/Thorn's Alpha 3, although it wasn't copied like-for-like - for example, the bowl on this hinges forwards whereas the Alpha 3's hinges backwards. When new, this lantern would have had a blue canopy - this has all but completely worn off now. A length of the lantern's bracket is still attached - it feels very loose in the spigot and yet will not pull out. The grub screws have seized and so some 'gentle persuasion' will be required to separate the lantern from the bracket.
A Fisher-Karpark NEMA socket is fitted to the canopy - this is likely to have been fitted in the factory rather than on-site at a later date.
As with the Atlas Alpha 3, a white spot is painted on the bowl to try to diffuse the light emitted from the lamp (and also as with the Alpha 3, the paint has partially been rubbed off!). Later versions of the Z8526 employed a revised bowl design with dedicated refractors.
The area immediately above the lamp is painted white, whilst the sides are in an unpainted aluminium finish. Owing to the presence of the NEMA photocell socket, additional terminations are provided.
A small plate beneath the lampholder provides the lantern's identification number. The "Code No." includes the manufacturing date code 'GA', which represents January 1975.
The grub screws used in securing the remains of the bracket were seized, and the only way to remove the outreach was to hammer it off. The lantern was deconstructed in late October 2017, and the canopy sent away for repainting. When it returned on Monday, 20th November, its appearance couldn't have been more different - the blue applied to the exterior had returned.
Meanwhile, the white paint finish of the area above where the lamp would be situated was repainted in gloss white.
The next step was to repaint the faded bowl spot. I hadn't dealt with a spot this size since I was a teenager, but employed a similar method to mask it this time, except that, as the spot would be spray, rather than brush-painted this time, newspaper was attached to the masking tape using parcel tape; this would prevent the rest of the bowl from being sprayed. Unusually, the paint was applied to the outer-facing side of the bowl.
After several separate coats of paint, the newspaper was removed and the bowl spot was complete again. The bowl was cleaned during this time as well.
The rear casting returned from receiving new grub screws in April 2018.
The four screws used in attaching the rear section to the canopy were in poor condition, and were replaced with bolts at the same time.
The re-assembled lantern was attached to a wall bracket on Friday, 27th April 2018.
An OSRAM 250 Watt HQI-E metal halide lamp was fitted, and the lantern switched on. The new diffuser spot worked surprisingly effectively.
Testing the lantern with my energy monitoring device revealed the following results:
| Test Voltage (V) | Current being drawn at full power (A) | Measured wattage (W) | Apparent Power (VA) | Frequency (Hz) | Power Factor | True Power (W) | Difference to rated wattage | Percentage Difference |
| 243.8 | 1.55 | 357 | 378 | 49.9 | 0.94 | 355.22 | 105.22 | 42.09% |
Thanks to the compatibility between metal halide and high pressure sodium lamp control gear, the Z8526 is able to run a 250 Watt SON-E lamp as an alternative.
Testing the lantern again with my energy monitoring device revealed the following results:
| Test Voltage (V) | Current being drawn at full power (A) | Measured wattage (W) | Apparent Power (VA) | Frequency (Hz) | Power Factor | True Power (W) | Difference to rated wattage | Percentage Difference |
| 246.2 | 1.71 | 333 | 421 | 50 | 0.79 | 332.59 | 82.59 | 33.04% |
Lamp warm-up video:
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